This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. The recently funded Morris K. Udall Parkinson's Disease Center of Excellence at Emory University is a highly collaborative research program in which electrophysiologists, pharmacologists, and anatomists work together to study the effects of existing and new treatments for parkinsonism from a circuit perspective. The center consists of four projects and two cores. Project 1 (Dr. Jaeger) examines changes imposed by altered basal ganglia input onto thalamic neurons in the parkinsonian state. Project 2 (Dr. Wichmann) is a series of experiments in parkinsonian primates to compare the thalamic effects of pallidal and subthalamic nucleus inactivation and stimulation, as are commonly used to treat advanced parkinsonism in patients, with the goal of identifying changes in thalamic activity that are associated with the antiparkinsonian effects of these procedures. Project 3 (Dr. Miller) is a series of translational experiments that examine the use of orally active TrkB receptor agonists as symptomatic or neurorestorative treatment for Parkinson's disease in different rodent and primate models. Project 4 (Dr. Conn, Vanderbilt) investigates the effects of novel subtype-selective muscarinic acetylcholine receptor antagonists and activators on basal ganglia activity, and on parkinsonism in rodent models. The projects are supported by an administrative core (Core A, Dr. Wichmann, PI;Dr. DeLong, Co-I, Dr. Pearson, administrator), and by an anatomy and behavior core (Core B, Dr. Smith) which provides immunohistochemistry and electron microscopy services to all of the center projects, and conducts behavioral testing in MPTP-treated monkeys under project 3.